A French prosecutor said bank account details of 79,000 customers was stolen from the Swiss subsidiary of HSBC, three times the number previously admitted by the bank.
Bosses at HSBC Private Bank (Switzerland) admitted last month that details of 24,000 bank customers were taken by an IT worker at the bank three years ago. However, analysis of the stolen files shows that they refer to 127,000 accounts maintained by 79,000 people, French prosecutor Eric de Montgolfier said on Wednesday, AFP reports.
French police obtained the encrypted files after raiding former HSBC computer specialist Herve Falciani's home in France back in January 2009. Authorities in France are seeking to use the data to investigate suspected tax evasion by wealthy French taxpayers.
Italian authorities are also interested in the data as part of a similar investigation into money laundering and tax evasion.
Information on 8,231 French account holders and 7,000 Italians is contained in the stolen data cache.
Swiss regulators are investigating whether HSBC broke bank privacy laws. HSBC has said it would refuse to help authorities hoping to use the stolen data for tax evasion investigations.
The case has raised questions both about banking privacy and the ethics of how far authorities ought to be allowed to go in chasing suspected tax dodgers. ®